1. Field of the Invention
The present invention relates to a composite material suitable for use for members of semiconductor manufacturing apparatus, and a method of producing the composite material.
2. Description of the Related Art
In general, members of semiconductor manufacturing apparatus, such as a bell jar, chamber, susceptor, clamp ring, and focus ring, are used often in chemically corrosive atmospheres including a halogen-based gas atmosphere and a high-density plasma atmosphere. Against this background, an yttrium oxide-containing material, which has high corrosion resistance and is less liable to be a contaminant source, has been considered for use in forming the members of semiconductor manufacturing apparatus, as disclosed in Japanese Patent Laid-Open No. 2001-181042.
A conventional yttrium oxide-containing material is, however, inferior in mechanical characteristics because the three-point bending strength thereof is about 140 to 180 MPa and the fracture toughness is about 0.8 to 1.1 MPa·m1/2. Therefore, when the conventional yttrium oxide-containing material is applied to the members of semiconductor manufacturing apparatus, those members can be broken when machined or used, which is disadvantageous in terms of yield, handing, and reliability.
The present invention has been made to solve the aforementioned problem, and an object thereof is to provide a composite material with excellent mechanical characteristics.